Various compositions and procedures are known for treating or modifying photographic paper and photographs using dyeing, coating or smoothing materials for obtaining desired effects such as with gums, shellacs, lacquers, alcoholic solvents, acids, oil pigments and waxes.
It is also known to apply polyhydric alcohols or alcohol ethers or alkyd resins and a dye solution to photographs and to drive the dye into the gelatin layer of photographs or to add an accelerator solution of distilled water and acetic acid whenever it is desired to obtain faster penetration of colloid surfaces of photographs. The prior art does not however make use of an anhydrous system or composition capable of obtaining the results of my invention and in particular does not use acetone-free diacetone which has a slower than alcohol evaporation time unique for my restoration of photographs to give time for rendition of detail.
Except for my U.S. Pat. Nos. 3,931,431 and 3,849,153 and the water-dye contents of Eastman Kodak Company publication of 1977 relating to basic developing, printing and enlarging in color, the prior art has no recognition or teaching directly applicable to my present invention and in fact is very varied and generally irrelevant.
To bring out further the distinctions of my invention over the prior art, U.S. Pat. No. 134,693 is concerned with black and white paper to which is applied color pigment, wax and oils but at the date of that patent in 1873, color gelatin emulsions on paper were unknown and hence the patent is not applicable to gelatin emulsions on paper or film of the Kodak type.
U.S. Pat. No. 949,708 involves an agent to absorb water from a color paper colloid gelatin prior to adding separate color dyes for restoration purposes in relation to packages, tubes and chemical storage problems.
U.S. Pat. No. 1,077,835 deals with gum or shellac for packaging and the uniting of dish-shaped flanged sections into a single unit and is unrelated to my present invention.
U.S. Pat. No. 1,139,682 describes the restoration of scratched motion picture films of ancient vintage using a fatty base and alcohol and is readily distinguishable from my invention.
U.S. Pat. No. 1,676,739 describes oils, crayons and wax pencils and must necessarily use a black and white paper, not a color emulsion as a substrate.
U.S. Pat. No. 2,327,854 describes crayons containing waxes and dyes together with oils for use on black and white photographic paper, but the oils cannot be used on color paper or directly over emulsions.
U.S. Pat. No. 3,445,176 describes a procedure that can be carried out only with steam and water and is extremely difficult to control and hence unsuitable for use by an amateur photographer to use acetic acid as a penetrant. This patent also notes that the choice of solvent is important.
U.S. Pat. No. 4,271,965 relates to chemical containers for dispensing film developing and processing mechanism and contains no teaching or suggestion of my invention, nor could the system of the patent be carried out by amateurs as it is complex and requires special controls.
U.S. Pat. No. 4,294,349 restores damaged porcelain dental prostheses and similar articles, using pigment-resin mixtures and has no relationship to the restoration of photographs and snapshots involved by my invention.